Telephone-exchange system



W. C. WEAVER.

TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED MAR. 25. 1918- RENEWED MAR. s. 1920.

1 ,353,872, Patented Sept. 28, 1920.

/nv/7f0/ Wf/hhm C. Weaver UNITED STATES PATENT OFFICE.

WILLIAM G. WEAVER, OF EAST ORANGE, NEW JERSEY ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK.

OF NEW YORK, N. Y., A CORPORATION TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. Patented Sept. 2 8, 1920.

Application filed March 25, 1918, Serial No. 224,516. Renewed March 5, 1920. Serial No. 363,592.

To all whom it may 0071 cern:

Be it known that I, WVILLIAM C. WVnAvnn,

a citizen of the United States, residing at East Orange, in the county of Essex, State of Yew Jersey, have-invented certain new and useful Improvements in Telephone-EX- change Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to such systems in which operator-controlled connecting circuits are employed.

Insystems or" this character it is frequently desirable to supplement the ordinary visual disconnection signal produced by a change in the condition of the signaling device upon the restoration of the receiver to the switchhook at one of the subscribers stations interconnected for conversational purposes, by an eifective auxiliary signal, preferably audible, which will invariably attract the attention of the operator. A peremptory signal of this nature tends to improve the service by promoting prompt disconnection or the connecting circuit upon the completion of the conversation thereover andthereby reducing the number of subscribers lines and connecting circuits which are ineffectively associated. Such a signal also serves to notify the operator readily that a recall is being initiated by one of the connected stations and enables momentar the supervisor to more closely observe the ser ice being rendered.

In accordance with a feature of this invention either or both supervisory relays of a connecting circuit are provided with means operable during each operation and each re lease of the 'associatedrelay to provide a y signal, which preferably may be audible in addition to the usuaperma nent changein the condition of the visual signaling device. 1

t is thought that the invention will be clearly understood from the following specification and the annexed drawing, Figure l of which diagrammatically illustrates one embodiment of the invention; while Fig. 2 illustrates a modified form thereof. p

In Fig. 1 of-the drawing a cord or connecting circuit C, which may be of any is provided at a central station for joining the subscribers stations A and B for conversational puiposes. The supervisorrelays 1 and 2 are each provided with contacts of the make-beiore-break type which, either upon the release, or upon the operation of the relay, cause an impulse of current to flow through an auxiliary relay 3, which relay may preferably be common to several cord circuits," thereby causing a momentary operation of a suitable audible signaling de vice i to supplement the usual accompanying change in condition of the associatec supervisory signaling lamp. The relay 3 may be sh '.1nted by condenser 20 for the well-lmown purpose of-aiding in the quick response of the relay.

Fig. 2 illustrates a slightly modified form of connecting circuit which may be used instead of the connecting circuit shown in Fig. 1. Such portions or" this circuit as are lCrv cal with the circuit of F1g. l have been omitted. In the modified system shown in Fig. 2, the usual supervisory relays l and 2 are equipped with the ordinary contacts and battery is supplied to such contacts through the windings of a differential relay 21 which is provided with make-beforebreak contacts for controlling the operation of the auxiliary relay 3.

It is thought that the invention may be more fully comprehended from the following description of the operation of the sy"- winding of relay v9 to ground, and consequently releasing the line relay 6 and extinguishing the line lamp 5 in the usual manner. Relay 1 also operates in the ordi nary manner over a circuit established from battery through a winding of repeating coil 13, winding of relay 1, ring contacts of the plug 7 and jack 8 through the switchhook contacts at station A, tip contacts of ack 8 and plug 7, and a second winding of repeating coil 13 to ground. The operation ofv relay 1 shunts the lamp 10 by the resistance 12', and thereby enti'nguishes the lamp in the usual manner. During the op- V eration of relay 1- the left-hand alternate contact is closed before the normal contact is opened and a temporary circuit is there: fore established ironi battery through lefthand alternate and normal contacts ofre- 7 lay 1 and winding of relay 3 to ground. Relay 3thcreupon completes a circuit, for a corresponding period, from battery through the audible signal device 4 and contact of relay 3 to ground, thereby producing an audible signal. When relay 1 is completely operated and its normal contact is opened, relay 3 releases and causes the cessation of the audible signal byopening the circuit of 1 The operator signals the subscriber at sta- A tionB in any sultable manner, and upon the removal of the receiver from .the switchhook at station B in answering the call a circuit is completed WhlCll causes the operation of relay 2'over a circuit established from battery through a Winding of repeat ing coil 13, Winding of relay 2, ring contacts of plug 14 andjack 15, switchhook contacts ofstation B, tip contacts of jack 15 and plug 14'and a second winding of repeating coil '13 to ground and the .consequentoperations in a manner similar tothat described for relay- 1. V

Assuming that the conversation is completedand the receiver at station Aislre- I stored, relay 1' is thereupon released due to the opening of its circuit at station A, and

by removing'the shunt aboutthe lamp 10' effects the lighting of this lamp in the ordi nary manner. VVhile releasing, however, relay 1 closes its normal. contact prior to the opening of 'jits left-hand alternate contact and completes a. temporary circuit for relay 3, similar to the circuit previously described,

tocause a momentary operation of the device-4 toiproduce a corresponding audible signal. ,When the receivercf station B is restored, relay 2 will'be-operated in a similar manner, causing the lighting of lamp 17 anda second.Inomentaryaud ble signal. All

apparatus returns to normal upon the re- 'moval of bothiplugs of the connecting. circuit from the-jacks of the, connecting lines. In case station desires to a re:

.means of these successive signals'the desire for another connection may be readily recognized by the operator as Well as by the supervisor. Station B may also notify the operator in the same manner when a recall is desired.

Referring to Fig. 2, assume that a call initiated by station A has been answered by the insertion of plug 7 of-the modified con necting circuit G into the jack 8.. The line lamp 5 is extinguished by the operation of the cutoff relay 9 and the supervisory relay 1 operates as described in connection with Fig.1. Supervisorylamp 10 is shunted by a circuitproceeding from battery through the left-hand Winding of relay 21, contact of re-. lay 1, resistances 12 and'll, sleeve contacts of plug 7 and jack 8, and winding of cutoff relay 9 to ground. Relay 21 thereupon operates and since the left-hand alternate contact thereof closes before the normal contact opens, a temporary circuit is established from battery through the left-hand alternate and normal contacts of relay 21 and winding of relay 3 to ground. Relay 3 thereupon operates and. completes a circuit for a corresponding period from battery through the signaling device 4, contact of relay 3 to ground, thereby producing an audible signal. W hen relay 21 is completely operated the. normal contact thereof opens,

releasing relay 3 and causing the cessation of the audible signal by interrupting the c rcuit through thesignahng device 4.

' Upon ascertaining that a connection is de sired with stationiB, the operator inserts plug 14 of the modifiedconnecting circuit into ack 15, operating cutoff relay 16, thus lighting supervisory lamp 17, and then signals station B,'as described in connection with Fig: 1, The removal of the receiver from the switchhook at station E also causes the operation of relay 2 as in the former case. .The supervisory lamp 17 is shunted by a circuit established from battery through the right-handfwinding of relav sleeve contacts of plu'g14 and jack 15, and winding of cutoff relay 16 to ground. Relay 21 thereupon releases, due to the differential arrangement of the windings thereof. and in releasing closes the normal contact before opening the lefthand alternate contact, thereby establishing a temporary circuit from battery through the left-hand alternate-and normal contacts of relay 21 and the winding of relay 3 to ground. Relay thereupon operates closing a circuitfor a corresponding period from battery 121, contact of relay 2, resistances. 19 and 13,

through signaling device 4-, and contact of relay 3 to ground, thereby producing an audible signal such as was produced in connection with the operation of relay 21.

Upon the completion or" the conversation, the restoration of the receiver to its switchhook at station A releases relay 1 and lights supervisory lamp 10 as described in connection with Fig. 1. Relay 21 operates due to the continued flow of current through the right hand winding, thereby causing a similar momentary audible signal to be produced by the signaling device 4. Upon the subsequent restoration of the receiver at station B, relay 2 is released, lighting supervisory lamp 1'? and, due to the interruption of the circuit through the right hand winding, relay 21 releases. Another similar audible signal is thereupon produced by the signaling device 1. .Upon the disconnection of both plugs the apparatus returns to normal.

It will also be evident that the movement of the switchhook at either station in connection with a recall will produce a series of momentary'audible signals similar to that produced in connection with the embodiment shown in Fig. 1.

While audible signals are produced upon the answering of a call by the operator and upon the answer of the called station, the service is not adversely affected thereby, sincethey are merely incidental to operations involved inthe' establishing of the connection.

Although the invention is shown and de scribed as being'associated with each supervisory relay, it may be desirable in some cases to furnish the additional signaling device in connection with the answering end of the link circuit only, since recalls are usually originated by the calling party and the restoration of the receiver at such station may serveto cause the operation. of the disconnect signal.

What is claimed is:

1. In a telephone exchange system, a plurality of lines terminating at a central oflice, a link circuit thereat for interconnecting the lines, a supervisory relay for the link circuit adapted to control a supervisory signaling device, an auxiliary relay, means controlled by the supervisory relay to send an impulse or" current through the winding of the auxiliary relay upon each energization and each deenergization of the supervisory relay, and

an auxiliary signaling device controlled by the auxiliary relay for producing an additional momentary signal for each signal produced by the supervisory signaling device.

2. In a telephone exchange system, a plurality of lines terminating at a central oflice, a link circuit thereat for interconnecting the lines, a supervisory relay for the link circuit adapted to control a visual supervisory signaling device, an auxiliary relay operable during each operating and each releasing period of the Supervisory relay, and an auxiliary signaling device controlled by the auxiliary relay to produce a momentary audible signal for each operation of the auxiliary relay.

3. In a telephone exchange system, a plurality of lines terminating at a central oi'lice, a link circuit thereat for interconnecting the lines, a supervisory relay for controlling the supervisory signaling device, an auxiliary relay, a temporary operating circuit for the auxiliary relay closed through contacts of the supervisory relay during each operating and each releasing period thereof, and an auxiliary signaling device adapted to produce a momentary signal upon each operation ofthe auxiliary relay.

l. In a telephone exchange system, a plurality of lines terminating at a central oflice, a link circuit thereat for interconnecting the lines, a supervisory relay for each end of the link circuit adapted to control a supervisory signaling device, an auxiliary relay, means controlled by either supervisory relay tosend an impulse of current through the winding of the auxiliary relay upon each energization and each deenergization of either supervisory relay, and an auxiliary signaling device controlled by the auxiliary relay.

5. In a telephone exchange system, a plurality of lines terminating at a central oflice, a link circuit thereat for interconnecting the lines, a supervisory relay for each end of the link circuit for controlling the condition of an associated supervisory signaling device, an auxiliary relay, a temporary operating circuit for the auxiliary relay closed through contacts of each supervisory relay during each operating and each releasing period thereof, and an auxiliary signaling device controlled by the auxiliary relay to produce signals similar in character upon each change in condition of either supervisory signaling device.

6. In a telephone exchange system, a plurality of lines terminating at a central ofiice, a link circuit thereat for interconnecting the lines, a supervisory relay for the link circuit for controlling a supervisory signaling device, an auxiliary relay, a passing contact for the supervisory relay adapted to send an impulse of current through the winding of the auxiliary relay upon each energization and each'deenergization of the supervisory relay, and an auxiliary signaling device controlled by the auxiliary relay.

In witness whereof, I hereunto subscribe my name this 19th day of March, A. D. 1918.

WILLIAM C. WEAVER. 

